The HSE has issued a warning after being notified of four further cases of measles in Dublin this week, bringing the total count to six.

Last month, two cases of the measles were identified after an adult and a child contracted the contagious illness.

It is likely that the two adults and two children that developed measles are likely to have been in contact with one of the two earlier cases in hospitals in Dublin.

It was reported last month that the two original patients, who returned to Ireland after being in mainland Europe, attended four hospitals in Dublin while at their most contagious.

Specialist in Public Health Medicine Dr Helena Murray said: "Measles can be a serious illness and is highly infectious. The best protection is to be fully vaccinated with two doses of MMR (Measles, Mumps, and Rubella) vaccine".

The risk of measles is for up to 21 days after contact with a case of measles. People who are most at risk are those who are not fully vaccinated with two doses of MMR vaccine or have not had measles in the past.

Measles symptoms include high fever, funny nose, red eyes and a red rash that starts on the head and spreads down the body.

Brown blotches or a flat red rash are signs to look out for, as well as vomiting, diarrhoea and tummy pain.

"The time between exposure to measles and developing the rash is usually 14 days," the HSE said.

"People are infectious from four days before rash starts until four days after."

The HSE are urging the public to remain vigilant and to stay at home if you think you have the measles.

Some 31 deaths are associated with measles in Europe this year so far, with most cases reported in Romania, France, Greece, and Italy.